Device and method for delivering shape-memory staples

ABSTRACT

An apparatus comprising a plurality of chambers for receiving an associated plurality of staples, each formed with a shape memory that allows the staple to adopt a straightened configuration, when placed in a stapler, and a deployed configuration for suturing when released from the stapler; and a sleeve moveable relative to the chambers between a first position, in which the staples are trapped by the sleeve within the chambers in the straightened configuration, and a second position, whereby the staples are freed to adopt the deployed configuration, wherein the sleeve is adapted to move between the first and second positions by rotating relative to the chambers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patentapplication Ser. No. 61/162,462, filed 23 Mar. 2009, and is acontinuation-in-part of International Application no. PCT/AU2008/000623,filed 2 May 2008, which claims priority to Australian provisional patentapplication no. 2007902314, filed 2 May 2007, the entire disclosure ofeach of which is hereby incorporated by reference.

TECHNICAL FIELD

The described embodiments relate generally to methods and devices fordelivering shape-memory staples. According to some embodiments, thedelivered shape-memory staples can be used for securing a graft toanother body.

BACKGROUND

In some types of surgery, it can be advantageous to use staples to affixtissue or grafts to other tissues or grafts. Such staples can serve tokeep the tissues and/or grafts together while the body heals orundergoes treatment.

Not all medical stapling devices are effective or optimal for eachsituation in which deployment of staples may be necessary or desirable.

The described embodiments address or ameliorate one or more shortcomingsor disadvantages associated with previous devices and/or methods fordelivering shape-memory staples or at least provide a useful alternativethereto.

SUMMARY

Some embodiments relate to an apparatus comprising:

a plurality of chambers for receiving an associated plurality ofstaples, each formed with a shape memory that allows the staple to adopta straightened configuration, when placed in a stapler, and a deployedconfiguration for suturing when released from the stapler; and

a sleeve moveable relative to the chambers between a first position, inwhich the staples are trapped by the sleeve within the chambers in thestraightened configuration, and a second position, whereby the staplesare freed to adopt the deployed configuration, wherein the sleeve isadapted to move between the first and second positions by rotatingrelative to the chambers.

Some embodiments relate to a device for delivering shape-memory staples,the device comprising:

a handle formed as a pistol grip;

a trigger actuator coupled to the handle;

a drive mechanism coupled to the trigger actuator and the handle; and

a delivery portion coupled to the drive mechanism, the delivery portioncomprising retention walls for retaining the staples within the deliveryportion in an elastically deformed configuration and release aperturesfor releasing the staples to adopt a deployed configuration based ontheir shape memory, wherein the delivery portion is configured to causeone end of each staple to protrude from the delivery portion in responseto actuation of the trigger actuator.

Some embodiments relate to a device for delivering shape memory staples,the device comprising:

a grippable portion;

a delivery portion coupled to the grippable portion, the deliveryportion comprising retention walls for retaining the staples within thedelivery portion in an elastically deformed configuration and releaseapertures for releasing the staples to adopt a deployed configurationbased on their shape memory, wherein the delivery portion is configuredto cause one end of each staple to protrude from the delivery portion inresponse to actuation of the first actuator; and

a head portion positioned at a tip of the delivery portion, the headportion being retractable in a proximal direction to cause the tip toflare outwardly.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are described hereinafter in further detail and by way ofexample, the detailed description of which should be read in conjunctionwith the accompanying drawings, in which:

FIG. 1 is a perspective view of a device for delivering shape-memorystaples;

FIG. 2A is an exploded perspective view of the device of FIG. 1, showinga proximal drive mechanism in further detail;

FIG. 2B is an exploded perspective view of part of an actuationmechanism of the device of FIG. 1;

FIG. 3 is an exploded perspective view of the device of FIG. 1, showinga striking mechanism in further detail.

FIG. 4 is an exploded perspective view of the device of FIG. 1, showinga head retraction actuator and barrel in further detail;

FIG. 5 is an exploded perspective view of an actuator clutch of thedevice, showing an outer clutch sleeve and delivery sleeve in furtherdetail;

FIG. 6 is an exploded perspective view of the actuator clutch, showingan inner clutch sleeve and expander rod in further detail;

FIG. 7A is an exploded perspective view of the actuator clutch, showinga core rod and drive clutch in further detail;

FIG. 7B is a perspective partial cutaway view of the actuator clutch,illustrating advancement of the core rod and drive clutch;

FIG. 8A is a side cross-sectional view taken along a vertical centreline of the device of FIG. 1, showing the device in an unactuated state;

FIG. 8B is a plan view of the device in the unactuated state, as shownin FIG. 8A;

FIG. 8C is a cross-sectional view of the actuator clutch and deliveryportion, taken along a vertical centre line similar to FIG. 8A;

FIG. 8D is a plan view of the actuator clutch and delivery portioncorresponding to FIG. 8C;

FIG. 9A is a side cross-sectional view taken along a vertical centreline of the device of FIG. 1, showing the device in a partially actuatedstate;

FIG. 9B is a plan view of the device in the partially actuated stateshown in FIG. 9A;

FIG. 9C is a cross-sectional view of the actuator clutch and thedelivery portion, taken along a vertical centre line similar to FIG. 9A,shown with the device in the partially actuated state;

FIG. 9D is a plan view of the actuator clutch and delivery portioncorresponding to the partially actuated state in FIG. 9C;

FIG. 10A is a side cross-sectional view taken along a vertical centreline of the device of FIG. 1, showing the device in a further actuatedstate;

FIG. 10B is a plan view of the device as shown in FIG. 10A in thefurther actuated state;

FIG. 10C is a cross-section of the actuator clutch and delivery portion,taken along a vertical centre line similar to FIG. 10A, showing theactuator clutch and delivery portion in the further actuated state;

FIG. 10D is a plan view of the actuator clutch and delivery portionshown in the further actuated state;

FIG. 11A is a side cross-sectional view taken along a vertical centreline of the device of FIG. 1, showing the device in a still furtheractuated state;

FIG. 11B is a plan view of the device in the still further actuatedstate shown in FIG. 11A;

FIG. 11C is a cross-sectional view of the actuator clutch and deliverportion, taken along a vertical centre line similar to FIG. 11A, showingthe actuator clutch and delivery portion in the still further actuatedstate;

FIG. 11D is a plan view of the actuator clutch and delivery portion inthe still further actuated state;

FIG. 12A is a side cross-sectional view of the actuator clutch anddelivery portion, taken along a plane angularly offset from the verticalcentre line of the device, showing the actuator clutch and deliveryportion in a final actuation state;

FIG. 12B is a plan view of the actuator clutch and delivery portionshown in the final actuation state;

FIG. 13A is a partial cutaway perspective view of a delivery portion ofthe device of FIG. 1, showing the delivery portion in the unactuatedstate;

FIG. 13B is a partial cutaway perspective view of the delivery portion,with the device in the partially actuated state;

FIG. 13C is a partial cutaway perspective view of the delivery portion,with the device in the further actuated state;

FIG. 13D is a partial cutaway perspective view of the delivery portion,with the device in a further partially actuated state;

FIG. 13E is a partial cutaway perspective view of the delivery portion,with the device shown in the final actuation state;

FIG. 14A is a partial side sectional view of the delivery portion, shownwhen the device is in the unactuated state;

FIG. 14B is a partial side sectional view of the delivery portion, shownwith the device in the partially actuated state;

FIG. 14C is a partial side sectional view of the delivery portion, whenthe device is in the further actuated state;

FIG. 14D is a partial side sectional view of the delivery portion, whenthe device is in the still further actuated state;

FIGS. 14E, 14F and 14G illustrate a progressive sequence of release ofthe staples to a deployed configuration, illustrating the deliveryportion in partial side cross-section; and

FIG. 15 is a partial plan view of a delivery sleeve of the device,showing insertion apertures and a release aperture for the staples.

Like reference indicators as between the drawings are intended toindicate like elements, features or functions. The drawings are not toscale and should be considered to be exemplary, for the purposes ofillustrating features and functions of the described embodiments.

DETAILED DESCRIPTION

The described embodiments relate generally to devices for deliveringshape-memory staples 910 and staple delivery methods performed usingsuch devices. In some embodiments, a staple delivery device 100comprises a striking mechanism 190 for delivering a striking blow tocause ends of the staples 910 to protrude in a stabbing manner, therebyenabling the staples 910 to penetrate dense and/or hardened substancessurrounding the staple delivery site.

In other embodiments, release apertures 554 for releasing the staples910 from a delivery portion 140 extend in a slight spiral relative to alongitudinal axis of the delivery portion 140. In still furtherembodiments, the device 100 comprises a somewhat bulb-shaped portion 660positioned at a delivery end of the device 100 and configured to beaxially withdrawn into the delivery end to cause a substantiallycylindrical sheath 550 around the delivery end to slightly flareoutwardly.

In some further embodiments, the device 100 may comprise a dome-shapedcap 145 at a distal end of the device 100 that is movable between aproximal position, in which an apron 147 at an open end 148 of the domedportion 145 fits around the cylindrical delivery tip 142, for example tohold a graft in place, where the graft is a substantially tubular graftfitting around at least part of the shaft 130 of the device 100, and adistal position. In the distal position, the dome-shaped cap 145 doesnot overlie the cylindrical end tip portion 142 and allows radialprotrusion of one end of each staple 910 into the graft, in preparationfor delivery of the staples to affix the graft to another body.

Embodiments of the device are shown and described in relation to FiguresIto 15, by way of non-limiting example. As shown in FIG. 1, device 100includes a grippable handle 110 having a palmar grip 111, a ratchet 112,a depressible trigger 150 and a finger grip portion 152. When device 100is held in a hand, grippable handle 110 is shaped to accommodate palmargrip 111 in a palm and/or thenar area of the hand, with fingersextending around trigger 150 and finger grip portion 152 so that device100 can be firmly held and operated. Trigger 150 is movable relative toratchet projections 113 a, 113 b and 113 c by squeezing the third,fourth and fifth fingers of the hand, for example. Ratchet 112cooperates with an angled trigger foot 155 at the base of trigger 150,which acts as a ratchet engagement portion, to hinder outward movementof trigger 150 relative to a main body of handle 110. Trigger foot 155can be actuated to successively engage ratchet projections 113 a, 113 band 113 c, with ratchet projection 113 a maintaining trigger 150 in anunactuated state.

Trigger 150 is pivotable relative to finger grip portion 152 of handle110 about an axis defined by a trigger pivot pin 151 received in a pinhole 153 formed in the finger grip portion 152. Trigger 150 has a splitclaw 154 formed at an opposite end to trigger foot 155 to engage aproximal drive mechanism 160 described below.

As shown in FIGS. 2A and 2B, handle 110 further comprises a movementlimiting bolt 115 positioned in a body of the handle 110 to limit inwardmovement of trigger 150. A spring 116 is positioned around movementlimiting bolt 115 and is at least partially received within the body ofthe handle 110 at one end and positioned around a spring registrationboss 117 formed on an inner face of trigger 150. Spring 116 serves tobias trigger 115 outwardly, so that trigger foot 155 sits against aratchet projection 113 a, 113 b or 113 c. Handle 110 also houses aretention bolt 118 to affix the proximal drive mechanism 160 to handle110.

Ratchet 112 is preferably formed of a flexible spring steel. Ratchet 112may be secured to a base 114 of handle 110 by base bolts 114 a receivedthrough ratchet apertures 112 a at one end of ratchet 112. Ratchetprojections 113 a, 113 b and 113 c are formed at an opposite end toapertures 112 a and ratchet 112 is sufficiently flexible so that trigger150 can be moved outwardly past one or more ratchet projections 113 a,113 b or 113 c (to reset trigger 150 after actuation) when ratchet 112is resiliently deflected downwardly away from the body of handle 110.

Handle 110 is coupled to an actuation portion 120 which comprises aproximal actuation portion 122 and a distal actuation portion 124. Ashaft 130 is coupled to distal actuation portion 124 to communicateactuation movements and forces to a delivery portion 140 positioned at adistal end of device 100.

In the context of this description, positional references are used,assuming that device 110 will be held in the manner of a pistol, withbase 114 being oriented generally downwardly and a “barrel” of the“pistol” extending generally outwardly. The relative term “proximal”should be interpreted to indicate a direction or position close to ortoward a palm of the hand when the hand is positioned around handle 110in the intended manner previously described. The term “distal” isintended to indicate a direction or position opposite to “proximal”,which will generally be away from the hand gripping handle 110. Theseand other positional references are provided for ease of understandingonly and are not intended to limit the actual position or orientation ofthe device during use.

Proximal actuation portion 122 includes proximal drive mechanism 160 anda striking mechanism actuable by a striking actuator 180.

As shown in FIG. 2A, proximal drive mechanism 160 comprises a proximaldrive sleeve 162 coupled to and resting against a top of handle 110.Proximal drive sleeve 162 has a proximal end insert 164 received throughan open proximal end of sleeve 162. An insert locator pin 211 isreceived through a correspondingly sized aperture in proximal end insert164 and through radial aperture 214 formed in proximal drive sleeve 162.Insert locator pin 211 remains partially received in radial aperture 214to fix proximal end insert 164 in position within sleeve 162. A drivespring 212 is also positioned within sleeve 162 so as to have one end ofthe spring positioned against an internal boss on proximal end insert164. Spring 212 is positioned partially around a projecting boss of aproximal end 222 of a first clutch portion 220 that is also receivedwithin proximal drive sleeve 162. Spring 212 serves to bias first clutchportion 220 in a distal direction.

Proximal drive sleeve 162 partially houses a second clutch portion 230that has a further slotted end 232 shaped to mate with a keying end 226of the first clutch portion 220. Second clutch portion 230 has a neckportion 234 positioned intermediate first slotted end 232 and a secondslotted end 236. Neck portion 234 is shaped to partially meet and engagewith split claw 154 of trigger 150 so that proximal actuation of trigger150 (i.e. by squeezing the fingers of the hand) causes distal movementof split claw 154, which engages second clutch portion 230 around neckportion 234 to cause second clutch portion 230 to move distally withinproximal drive sleeve 162.

A staple release actuator 165, generally formed as a projecting leverand indicated as “Lever D” in the drawings is coupled to first clutchportion 220 by a screw threaded coupling through threaded hole 224formed in first clutch portion 220. A moment applied to staple releaseactuator 165 causes rotation of first clutch portion 220 about alongitudinal axis of device 100. This rotational movement of firstclutch portion 220 causes like rotational movement of second clutchportion 230, which in turn causes like rotation of a drive clutch 740(described in further detail below) to move part of delivery portion 140relative to outer delivery sleeve 550 (where permitted by thepositioning of release actuator limiting rod 812 within release actuatorlimiting channel 512, as described below).

Proximal drive sleeve 162 has an enlarged distal end with a malethreaded cylindrical wall 218 for threaded engagement with barrelhousing 410 (FIG. 4). A top screw 178 is insertable through ascrew-receiving aperture 418 in barrel housing 410 and into a threadedaperture 168 formed in the distal end of proximal drive sleeve 162 tofix barrel housing 410 to proximal drive sleeve 162.

A spring 250 and positioning element 260 are received in the distal endof proximal drive sleeve 162 and in the proximal end of barrel housing410 to receive and position second slotted end 236 relative to a clutchhead portion 742 of drive clutch 740.

Proximal drive sleeve 162 has a slotted aperture 216 formed toward adistal end of sleeve 162 to receive a striking transmission portion 188of anvil 186 therethrough. Striking transmission portion 188 isconfigured to project downwardly from within a generally cylindricalstriking actuator housing 181 through slotted aperture 216 to bereceived in neck portion 234. Opposed claws of split claw 154 may besized to fit around the reduced diameter portion of neck portion 234 andto at least partially receive a lower extremity of striking transmissionportion 188. Thus, movement of either of anvil 186 and trigger 150causes movement of second clutch portion 230 along its longitudinalaxis.

As shown in FIG. 3, striking mechanism 190 comprises a striking piston185 axially movable within striking actuator housing 181 (formed as ahollow cylinder) to act as a hammer upon anvil 186 under the action of astriking actuator spring 183 proximally positioned within housing 181. Astriking actuator 180, formed as a lever, and shown in the drawings as“Lever C”, may be coupled to striking piston 185 by means ofscrew-threaded engagement. Striking actuator 180 extends radiallythrough an L-shaped guide channel 182 formed in housing 181. Part ofguide channel 182 extends circumferentially to allow for rotationalmovement of striking actuator 180 and striking piston 185 within housing181. However, housing 181 also defines a longitudinal section of guidechannel 182 that permits striking actuator 180 to move longitudinallywithin that section of guide channel 182.

One end of spring 183 is positioned against an end cap 187 secured at aproximal end of housing 181, for example by screw threaded engagement.The other end of spring 183 acts on an inner cap 184 having a bossaround which fits the end of spring 183. Inner cap 184 abuts a proximalend of striking piston 185 so that, under the action of spring 183,striking piston 185 is biased in the distal direction.

When striking actuator 180 is in an unactuated position, it is receivedwithin the circumferential portion of guide channel 182, in which thepart of striking actuator housing 181 that defines guide channel 182hinders distal movement of striking actuator 180. In order to actuatestriking actuator 180 (move it into an actuated position), strikingactuator 180 may have a moment applied to rotate it toward thelongitudinal section of guide channel 182 so that striking piston 185and striking actuator 180 become free to move in the distal directionunder the biasing action of spring 183.

Striking actuator housing 181 may be secured to proximal drive sleeve162 by receipt of a proximal end screw 166 through an aperture formed ina downwardly pending positioning flange 312 formed on or attached tohousing 181. A threaded end of proximal end screw 166 may be received ina matingly threaded proximal end of proximal end insert 164 in order tosecure proximal end screw 166 in position and thereby assist in fixedlylocating housing 181 on top of, and adjacent to, proximal drivemechanism 160. Axes of movement of the mechanisms within proximal drivemechanism 160 and striking mechanism 190 are generally longitudinal andparallel.

As an additional means of securing housing 181 relative to proximaldrive sleeve 162, a distal end 314 of housing 181 is configured to matewith and receive a positioning boss 322 located toward a distal end ofproximal drive sleeve 162. Positioning boss 322 is fixed relative to thecylindrical barrel of proximal drive sleeve 162 and is positioned to beslightly above a distal end of slotted aperture 216.

Referring also to FIG. 4, head retraction actuator 170 and barrelhousing 410 are described in further detail. Head retraction actuator170 comprises a bar 171 received within a bar receiving channel 174defined by' a head portion of a rotation key 173. A ball 172 is receivedin an aperture formed in a shaft of rotation key 173 in order to fix bar171 in position relative to channel 174. Rotation key 173 has a cam 175on an inner end thereof for engaging and proximally shifting innerclutch sleeve 610 (FIG. 6) by a camming engagement of a distal face 611a of proximal end flange 611 of inner clutch sleeve 610. Rotation key173 is received within registration barrel 176, which is received byscrew-threaded engagement with actuator insert port 414 formed in oneside of barrel housing 410. Registration barrel 176 has a male screwthread 177 for engaging with a corresponding female screw thread withinactuator insert port 414.

Barrel housing 410 comprises a threaded proximal end 412 sized to fitaround and engage with threaded cylindrical wall 218 of proximal drivesleeve 162. Barrel housing 410 also comprises an internal annular flange420 within which sits positioning element 260. At its distal end, barrelhousing 410 has a threaded distal end 416 from which upper and lowerregistration bosses 422 extend distally to register and mate withregistration notches 522 formed at corresponding upper and lowerpositions on external annular flange 442 of actuator clutch 440.

A retention cap 128 slides over a distal end of actuator clutch 440 toretain actuator 440 within barrel housing 440. Retention cap 128 has aninternal thread 426 to engage with threaded distal end 416 of barrelhousing 410 and has an internal annular flange 432 to engage and abut adistal face of external annular flange 442, to thereby retain actuatorclutch 440 within barrel housing 410. A distal opening in retention cap128 allows a distal portion of actuator clutch 440 to extendtherethrough, along with shaft 130.

Head retraction actuator 170, also shown in the drawings as “Lever B”,can be partially rotated about a central axis of rotation key 173, whichis normal to the longitudinal axis of device 100. This rotation causesretraction of a somewhat bulb-shaped expander head 660 within deliveryportion 140, thereby causing delivery sleeve 550 to flare outwardlysomewhat adjacent delivery tip 142.

It should be noted that the length of shaft 130 is depicted in FIGS. 2A,3, 4, 5, 6, 7A and 7B as being quite short. This is done for ease ofillustration only and does not represent the actual length of shaft 130.Rather, the relative length of shaft 130 as shown in FIG. 1 is intendedto more accurately reflect the intended configuration of device 100,although it is to be noted that the drawings are not to scale.

Referring also to FIGS. 5 and 6, actuator clutch 440 is shown anddescribed in further detail. Actuator clutch 440 comprises an outerclutch sleeve 510 and an inner clutch sleeve 610. Outer clutch sleeve510 mostly surrounds inner clutch sleeve 610, except for a proximal endflange 611 which extends radially outwardly to an extent that itcircumferentially coincides with an outer circumference of outer clutchsleeve 510. Outer clutch sleeve 510 and inner clutch sleeve 610 haveradial apertures 514 and 614 to accommodate a locating cylinder 630 andradial screw apertures 516 and 616 to allow for insertion of a fixationscrew 538 to affix inner delivery sleeve 820 an inner rotatable part ofactuator clutch 440.

The generally cylindrical wall of outer clutch sleeve 510 defines arelease actuator limiting channel 512, having a generally L-shapedconfiguration. Release actuator limiting channel 512 receives a head ofrelease actuator limiting rod 812 therein in a manner such that channel512 limits relative movement between outer clutch sleeve 510 andlimiting rod 812. Limiting rod 812 is coupled to internal parts ofactuator clutch 440 and is indirectly coupleable to proximal drivemechanism 160 as described below, and plays an important role inavoiding premature actuation of staple release actuator 165.

Outer clutch sleeve 510 has an outer sleeve proximal end opening 524,through which a proximal end of inner clutch sleeve 610 is received, andan outer sleeve distal end opening 526, through which a proximal portionof the shaft 130 extends. A distal end 542 of outer clutch sleeve 510has a number of circumferentially spaced fixation apertures 537 forreceiving fixation screws 536 to secure delivery sleeve 550 within outersleeve distal end 542. Outer clutch sleeve 510 also defines an annularwall 546 toward distal end 542, against which a spring 562 andpositioning ring 530 are located. Spring 562 serves to bias someinternal components of actuator clutch 440 in the proximal direction.Spring 562 is positioned internally of positioning ring 530, which hasapproximately the same inner diameter as inner clutch sleeve 610.

The components of shaft 130 are generally coaxial with inner and outerclutch sleeves 610, 510, barrel housing 410 and proximal drive mechanism160, although striking mechanism 190 is axially offset therefrom.

Distal actuation portion 124 includes head retraction actuator 170,barrel housing 410, actuator clutch 440, shaft 130 and delivery portion140.

As shown in FIG. 5, outer delivery sleeve 550 has a proximal endreceived within outer sleeve distal end opening 526 and affixed to outersleeve distal end 542 by fixation screws 536. At its distal end, outerdelivery sleeve 550 has a number of release apertures 554, formed asgenerally longitudinally extending slots in the end of outer deliverysleeve 550. Release apertures 554 extend all the way to the distalextremity of outer delivery sleeve 550, thereby defining fingers 552arranged in an interrupted cylindrical configuration. Fingers 552 definea generally angled inner profile at the distal opening of outer deliverysleeve 550 to accommodate engagement with a corresponding angled outersurface 662 of expander head 660. When expander head 660 is withdrawnslightly in the proximal direction, angled outer surface 662 engages andslides against angled inner profile 558 which, because fingers 552 areformed of a resiliently deflectable material, causes the fingers 552 todeflect slightly radially outwardly, thereby causing delivery tip 142 toflare outwardly. This outward flaring can assist in forcibly expandingvessel walls, for example, and can enable release of the staples at aradially increased position which, considering the generally circularshape memory of the staples, can lead to improved medical staplingquality.

Delivery sleeve 550 also defines insertion apertures 556 through whichdeformed (i.e. relatively straightened) staples can be inserted so as tobe received within staple receiving chambers 826. Insertion apertures556 may be formed as slots that are generally parallel to, but offsetfrom, release apertures 556. Insertion apertures 556 are of asubstantially shorter length than release apertures 554 and arepositioned close to, but slightly proximally of, the proximal extremityof release apertures 554.

Inner clutch sleeve 610 defines a release actuator limiting channel 612to permit movement of release actuator limiting rod 812 in proximal anddistal directions, but not axially. When limiting rod 812 is allowed tomove rotationally within limiting channel 512, limiting rod 812 causesinner clutch sleeve 610 to rotate along with limiting rod 812. Thiscauses rotation of expander rod 650 to which inner clutch sleeve 610 isrotatably coupled by a locating cylinder 630. Specifically, expander rod650 has its proximal end 652 received through a diametrical through hole632 formed in locating cylinder 630. A fixation screw 636 is positionedaxially within locating cylinder 630 to fix expander rod 650 relative tolocating cylinder 630.

As shown in FIG. 6, expander head 660 is positioned at the distal end ofexpander rod 650 and has staple protrusion slots 664 extending in agenerally axial but outward direction on the outside of expander head660 to accommodate protrusion of staples 910 from within staplereceiving chambers 826. Expander head 660 also has a shoulder 668against which distal ends 824 of inner delivery sleeve 820 abut wheninner delivery sleeve 820 is moved to its distal-most position. Angledouter surface 662 transitions from shoulder 668 to the radial and distalextremity of expander head 660, which generally positionally coincideswith delivery tip 142.

Expander rod 650 comprises a generally hollow cylindrical wall 651through which core rod 710 passes and is movable. Expander rod 650 isreceived within inner delivery sleeve 820, which is in turn receivedwithin outer delivery sleeve 550. Core rod 710 has a rod proximal end712 and a rod distal end 714. Distal end cap 145 is positioned at thedistal end 714. Distal end cap 145 may comprise a flexible medical gradeplastic apron 147 extending proximally from the distal extremity ofdistal end cap 145. Apron 147 is intended to have enough firmness tohold a graft onto distal tip 142 in the unactuated position.

Proximal end 712 of core rod 710 is received within a diametricalthrough-hole 722 of a locating cylinder 720. Core rod 710 is affixed tolocating cylinder 720 by a fixation screw 730 axially received withinlocating cylinder 720. Core rod 710 extends through diametricalthrough-hole 722 to be at least partially received within a central bore743 of drive clutch 740. Drive clutch 740 also has a transverse bore 744to accommodate locating cylinder 720. This arrangement is such that,when second clutch portion 230 engages clutch head portion 742,rotational or axial force applied to second clutch portion 230, forexample by any of Levers A, C and D, such force is transmitted to corerod 710 and to components housed within inner clutch sleeve 610.

Drive clutch 740 has distal annular wall portions 746 arranged tointerleave with and abut corresponding circumferentially spaced annularwall portions 840 to limit excessive distal movement of drive clutch 740responsive to second clutch portion 230 and permit a clutching actionfor rotation transfer.

Referring now to FIGS. 8A to 8D, an unactuated position of device 100 isdescribed. In the unactuated position, first and second clutch portions220, 230, anvil 186 and drive clutch 740 are located in relativelyproximal positions according to their limited freedom of movement withintheir respective housings. In this state, because of the position oflimiting rod 812 within limiting channel 512, outer clutch sleeve 510and inner clutch sleeve 610 cannot rotate relative to each other andlimiting rod 812 is prevented from rotating relative to outer clutchsleeve 510. As a result, inner delivery sleeve 820 is prevented fromrotating within outer delivery sleeve 550.

In the unactuated state, distal end cap 145 is at its proximal-mostposition, in which open end 148 of domed-shaped apron 147 partiallyoverlies distal delivery tip 142, thereby hindering accidentalprotrusion of staples 910 from delivery tip 142 prior to their intendedrelease.

It is intended that staples 910 be inserted into staple receivingchambers 826 in their deformed (straightened) configuration when device100 is in the unactuated state.

Referring now to FIGS. 9A to 9D, device 100 is described in relation toa first actuation state, which is one of several possible actuationstates. The first actuation state is achieved by forcing lever 150 tomove proximally, for example by squeezing fingers to cause them to curlinwardly towards a hand gripping handle 110, so as to move trigger foot155 inwardly by one ratchet position. The levering action of trigger 150about trigger pivot pin 151 causes split claw 154 to move distally. Thisin turn forces second clutch portion 230 in a distal direction, which inturn causes drive clutch 740 and core rod 710 to move distally by acertain amount, such as a few millimetres, for example.

After the first actuation, distal annular wall portions 746 of driveclutch 740 advance to be adjacent proximal annular wall portions 840, soas to be able to rotationally engage therewith. Thus, distal annularwall portions 746 effectively provide interleaving fingers to interleavewith corresponding proximal annular wall portions 840 in order totransmit rotational force from drive clutch 740 to annular wall portions840, which are in turn rigidly coupled to limiting rod 812 and innerdelivery sleeve 820. In the first actuation state, limiting rod 812remains in its proximal-most position within limiting channel 512. Thepurpose of the first actuation is to distally progress distal end cap145 so as to allow subsequent protrusion of staples 910 from distaldelivery tip 142 and to engage drive clutch 740 with annular wallportions 840 (to act as a clutch).

Referring now to FIGS. 10A to 10D, a second actuation state of device100 is described in further detail. In the second actuation state, headretraction actuator 170 (Lever B) is twisted so that, instead of bar 171being generally horizontal and parallel to barrel housing 410, it isrotated 90 degrees anticlockwise (as seen in FIG. 10A) so that bar 171is positioned vertically. By thus rotating bar 171, rotation key 173 iscaused to rotate counter-clockwise, which causes cam 175 to engagedistal face 611 a of proximal end flange 611 to shift inner clutchsleeve 610 in a proximal direction by an amount configured according tothe shape of clutch 175. For example, inner clutch sleeve 610 may bemoved proximally by about 0.5 mm under the action of cam 175.

Retraction in the proximal direction of inner clutch sleeve 610 causesexpander rod 650 to be shifted proximally by the same amount, while corerod 710, outer delivery sleeve 550 and inner delivery sleeve 820 remainunmoved, except for a slight flaring of outer delivery sleeve 550 atdistal tip 142, as described previously. The flaring of delivery portion140 is caused by the action of the angled outer surface 662 of expanderhead 660 acting on the angled inner profile 558 of fingers 552, therebyoutwardly deflecting fingers 552. This flaring of distal tip 142 may beconfigured to result in an increased diameter of approximately 1 to 2mm, for example.

The second actuation step achievable by actuation of head retractionactuator 170 is not necessary to achieve release of the staples 910, butmay be desirable to provide greater expansion of a vessel wall. It isconsidered that this may provide improved stapling quality.

Referring now to FIGS. 11A to 11D, third and fourth actuation states aredescribed in further detail. In the third actuation state, trigger 150is depressed proximally in a further step so that trigger foot 155 restsproximally of ratchet projection 113 c, which causes split claw 154 tofurther advance second clutch portion 230 in a distal direction. Thiscauses inner sleeve 820 to be pushed distally by drive clutch 740,thereby advancing staples 910 positioned within staple receivingchambers 826. When staples 910 are received within staple receivingchambers 826, jagged or irregular inner chamber walls 822 partiallydefining the staple receiving chambers 826 serve to frictionally engagestaples 910 so as to encourage them to advance within their respectivechambers. An additional or alternative advancement means is provided byinward detent 828 formed in inner delivery sleeve 820 to coincide withstaple receiving chambers 826. The inward detents 828 are formed so asto allow each staple 910 to at least partially nest therein based ontheir shape memory, which is configured to cause them to adopt anapproximately circular deployed configuration. As inner delivery sleeve820 progresses distally, inner chamber walls 822 and/or inward detents828 assist in moving staples 910 so that one end thereof passes throughstaple protrusion slots 664 and extends somewhat radially outwardly fromtip portion 142. This third actuation state allows for partialprotrusion of the staples 910, for example to cause them to protrude atleast partially through a graft positioned around delivery tip 142.

Inward detents 828 are formed as radially inwardly curved (concave)deformations in inner delivery sleeve 820 adjacent delivery sleevedistal ends 824. Detents 828 provide axial engagement as well assuitable orientation of the staples 910 so that when freed, the staples910 have their ends come together at a position outside and away fromdelivery portion 140 (as illustrated in FIGS. 13E and 14A). If thestaples 910 are not oriented properly within receiving chambers 826,their ends may not come together in the right position to achieve thedesired stapling effect.

In a fourth actuation state, striking mechanism 190 is actuated todeliver a striking blow to inner delivery sleeve 820 within deliveryportion 140. The striking blow is communicated to delivery portion 140by the application of a moment to lever 180 so as to rotate strikingpiston 185 and lever 180 into a position where spring 183 biases thestriking portion 185 in a distal direction, thereby causing strikingpiston 185 to act as a hammer upon anvil 186, which communicates thekinetic impact of the hammer blow to second clutch portion 230 viastriking transmission portion 188 of anvil 186. Second clutch portion230 thus receives a kinetic impulse in the distal direction, which iscommunicated to drive clutch 740 through abutting contact of secondclutch portion 230 with drive clutch 740. Drive clutch 740 in turncommunicates the kinetic impulse to annular wall 840 which is coupled tothe inner delivery sleeve 820.

The distally directed kinetic impulse communicated from the strikingmechanism 190 is configured to cause further protrusion of theprotruding staples 910 in an approximately stabbing manner. Theintention of such stabbing protrusion of staples 910 is to causeprotruding ends of staples 910 to be able to break through relativelydense tissue or substances that may have formed on the vessel wallswhere the join is desired to be made.

Delivery of the striking blow in response to actuation of the strikingmechanism 190 is an optional step that can be omitted if desired.Additionally, according to some embodiments, striking mechanism 190 mayprovide more than one circumferential slot position for lever 180. Thisis so that greater or lesser compression of spring 183 in the proximaldirection may be achieved in order to provide greater or lesser kineticimpact upon anvil 186 when striking mechanism 190 is actuated.

Referring also to FIGS. 12A and 12B, a fifth and final actuation stateis described in further detail. Because the advancement of drive clutch740 also distally advanced annular wall 840 and therefore advancedlimiting rod 812 relative to outer clutch sleeve 510, completion of thethird actuation state enables the final actuation state (i.e. release ofthe staples) to be performed. This is because the distal movement oflimiting rod 812 relative to outer clutch sleeve 510 and limitingchannel 512 positions limiting rod 812 to be able to slide laterallywithin limiting channel 512. This allows rotation of inner deliverysleeve 820 within outer delivery sleeve 550 as shown in FIGS. 12A and12B, so that the longitudinally extending staple receiving chambers 826coincide with release apertures 554, thereby freeing staples 910 toadopt a circular deployed configuration (920) according to their shapememory.

Because of the thinness of the wire used for staples 910, 920 and thestrong shape memory induced in such staples, the ends of the staples aresharp enough and come together with enough force to penetrate the tissuesurrounding delivery tip 142. Although FIGS. 11A to 11D, 12A and 12Dshow the distal delivery tip 142 being flared, this need not necessarilybe the case. Actuation of staple release actuator 165 causes release ofstaples 910 through release apertures 554 whether delivery tip 142 isflared or not.

The rotation of inner delivery sleeve 820 relative to outer deliverysleeve 550 is caused by application of a moment to staple releaseactuator 165, such as by pressing it downwardly. Such a downwardmovement applied to staple release actuator 165 (Lever D) causesrotation of first clutch portion 220, which transmits rotationalmovement to annular wall portions 840 via a second clutch portion 230and drive clutch 740. As annular wall portions 840 are coupled to innerdelivery sleeve 820, the downward moment applied to Lever D causes thelongitudinally extending staple receiving chambers 826 to align withrelease apertures 554 to allow staples 910 to spring outwardly and adopttheir deployed configuration.

FIGS. 13A, 13B, 13C, 13D and 13E illustrate the unactuated state, thefirst actuated state, the second actuated state, the third actuatedstate and the fifth and final actuated state, progressively.Illustration of the further projection resulting from actuation of thestriking mechanism 190 is not shown as a'distinct state separate to thatof FIG. 13D, but FIG. 13D may be considered to depict the result of acombination of the third and fourth actuation states, as describedabove.

Similarly, FIGS. 14A to 14G illustrate the configuration of deliveryportion 140 during progressive actuation states. FIGS. 14A, 14B, 14C and14D respectively correspond to the unactuated state, the first actuationstate, the second actuation state and third and fourth actuation states.FIGS. 14E, 14F and 14G progressively illustrate the fifth actuationstate, in which the release of staples 910 from release apertures 554 isillustrated for embodiments of device 100 in which release apertures 554are formed to have a slight spiral (i.e. to be slightly angledrelatively to a longitudinal axis, as illustrated in FIG. 15).

For embodiments in which the release apertures 554 are angled, therelease apertures 554 are configured so that, while distal ends of thestaples 910 protrude from delivery tip 142, at an initial stage ofrelease only a proximal part of release apertures 554 comes intoalignment with the underlying staple receiving chambers 826. This allowsa proximal end of each staple 910 to begin to curl outwardly fromchambers 826 as a result of its shape memory. This initial protrusion ofthe proximal ends of staples 910 at the beginning of the release stageis illustrated in FIG. 14E.

As can be seen in FIG. 14F, as inner delivery sleeve 820 progressivelycomes more into alignment with release apertures 554, more of theproximal end of each staple is freed to adopt its deployedconfiguration, although the staple 910 is not yet completely freed. AsFIG. 14F illustrates, the proximal end of each staple 910 tends to curlupwardly so that, once the inner delivery sleeve 820 is brought intofurther alignment with release apertures 554, as shown in FIG. 14G theopposite ends of each staple 910 are allowed to come together in apinching and piercing action which is considered to be more effectivefor some stapling purposes than if there were no progressive release ofthe proximal end of each staple 910.

Although FIGS. 14A to 14G illustrate the release of only one staple 910into a deployed configuration 920, this is for simplicity ofillustration only and it should be understood that multiple staples arereleased at the same time from a number of different circumferentiallyspaced positions. Device 100 can be configured to have four, five, six,seven, eight, nine, ten, eleven or twelve release apertures 554 (and acorresponding number of insertion apertures 556), depending on whichconfiguration may be suited for a particular stapling application.Additionally, although staples 910 appear to be bent between shoulder668 and delivery tip 142 in FIGS. 14A to 14F, such bending of the stapledoes not occur in quite the way it is illustrated. Rather, such bending,if it occurs, will be rather smooth, instead of being a sharp bend inthe wire.

The angle of release apertures relative to the longitudinal axis ofouter delivery sleeve 550 is relatively shallow, such as about 1 degreeto about 7 degrees, for example. The angle may be varied, depending onthe number of release apertures 554 provided in delivery portion 140.

The wire used as staples 910, 920 may be nitinol wire, for example, witha diameter of between about 0.1 mm to about 0.5 mm. Some specificembodiments are configured to deploy staples of about 0.3 mm or about0.33 mm in diameter.

The use of shape-memory staples as described herein avoids the need forstaples to be deformed by being forced against an anvil to adopt thedesired staple shape, thus obviating the extra components and logisticaldifficulties associated with having an anvil at the staple delivery endof the stapler.

While embodiments are described herein in specific detail, it is to beunderstood that such embodiments are described by way of example and arenot to be construed to be limiting with respect to equivalents or tolimit the scope of the invention.

Throughout this specification and claims which follow, unless thecontext requires otherwise, the word “comprise”, and variations such as“comprises” and “comprising”, will be understood to imply the inclusionof a stated integer or step or group of integers or steps but not theexclusion of any other integer or step or group of integers or steps.

PARTS LIST

-   -   100 stapler    -   110 handle    -   111 palmar grip    -   112 ratchet    -   112 a bolt holes    -   113 a, b, c ratchet projections    -   114 handle base    -   114 a base bolts    -   115 movement limiting bolt    -   116 biasing spring    -   117 spring registration boss    -   118 retention bolt    -   120 actuation portion    -   122 proximal actuation portion    -   124 distal actuation portion    -   128 retention cap    -   130 shaft    -   140 delivery portion    -   142 delivery tip    -   145 distal end cap    -   147 apron    -   148 open end of apron    -   150 trigger (Lever A)    -   151 trigger pivot pin    -   152 finger grip portion    -   153 pin hole    -   154 split claw    -   155 ratchet engagement portion/trigger foot    -   160 proximal drive mechanism    -   162 proximal'drive sleeve    -   164 proximal end insert    -   165 staple release actuator (Lever D)    -   166 proximal end screw    -   170 head retraction actuator (Lever B)    -   171 bar    -   172 ball    -   173 rotation key    -   174 bar receiving channel    -   175 cam    -   176 registration barrel    -   177 screw thread    -   178 top screw    -   180 striking actuator (Lever C)    -   181 striking actuator housing    -   182 guide channel    -   183 striking actuator spring    -   184 inner cap    -   185 striking piston/hammer    -   186 anvil    -   187 end cap    -   188 striking transmission portion    -   190 striking mechanism    -   211 insert locator pin    -   212 drive spring    -   214 radial aperture    -   216 slotted aperture    -   218 threaded cylindrical wall    -   220 first clutch portion    -   222 clutch proximal end    -   224 threaded hole    -   226 keying end    -   230 second clutch portion    -   232 first slotted end    -   234 neck portion    -   236 second slotted end    -   250 spring    -   260 positioning element    -   312 positioning flange    -   314 distal end    -   322 positioning boss    -   410 barrel housing    -   412 threaded proximal end    -   414 actuator insertion port    -   416 threaded distal end    -   418 screw receiving aperture    -   420 internal annular flange    -   422 registration boss    -   426 internal thread    -   432 internal annular flange    -   440 actuator clutch    -   442 external annular flange    -   510 outer clutch sleeve    -   512 release actuator limiting channel    -   514 aperture for locating cylinder    -   516 screw aperture    -   522 registration notch    -   524 outer sleeve proximal end opening    -   526 outer sleeve distal end opening    -   530 positioning ring    -   536 fixation screw    -   537 fixation aperture    -   536 fixation screw    -   542 outer sleeve distal end    -   546 annular wall    -   550 outer delivery sleeve    -   552 fingers    -   554 release aperture    -   556 insertion apertures    -   558 angled inner profile    -   562 spring    -   610 inner clutch sleeve    -   611 proximal end flange    -   611 a distal face of proximal end flange    -   612 release actuator limiting channel    -   614 aperture for locating cylinder    -   616 screw aperture    -   618 inner sleeve distal end    -   630 locating cylinder    -   632 diametrical through-hole    -   636 fixation screw    -   650 expander rod    -   651 cylindrical wall    -   652 proximal end    -   660 expander head    -   662 angled outer surface    -   664 staple protrusion slots    -   668 shoulder    -   710 core rod    -   712 rod proximal end    -   714 rod distal end    -   720 locating cylinder    -   722 diametrical through-hole    -   730 fixation screw    -   740 drive clutch    -   742 clutch head portion    -   743 central bore    -   744 transverse bore    -   746 distal annular wall portions of drive clutch    -   812 release actuator limiting rod    -   820 inner delivery sleeve    -   822 chamber inner wall    -   824 delivery sleeve distal end    -   826 staple receiving chambers    -   828 inward detent    -   840 annular wall portions (coupled to inner delivery sleeve)    -   910 staples (deformed configuration)    -   920 staples (deployed configuration)

1. An apparatus comprising: a plurality of chambers for receiving anassociated plurality of staples, each formed with a shape memory thatallows the staple to adopt a straightened configuration, when placed ina stapler, and a deployed configuration for suturing when released fromthe stapler; and a sleeve moveable relative to the chambers between afirst position, in which the staples are trapped by the sleeve withinthe chambers in the straightened configuration, and a second position,whereby the staples are freed to adopt the deployed configuration,wherein the sleeve is adapted to move between the first and secondpositions by rotating relative to the chambers.
 2. The apparatus asclaimed in claim 1, wherein the shape memory is at least partiallythermally activated.
 3. The apparatus of claim 1, wherein the sleeve hasa plurality of openings which serve as entry points for staples to beloaded into the chambers and wherein the sleeve has a plurality ofelongate exit grooves for discharge of the staples into the deployedconfiguration.
 4. The apparatus of claim 3, wherein the exit grooves areradially offset from the openings.
 5. The apparatus of claim 1, furthercomprising a carrier that comprises the chambers and the chambers arearranged to initially align with the openings for loading the staplesinto the carrier and to subsequently align with the exit grooves whenthe sleeve is rotated relative to the carrier for discharge of thestaples.
 6. The apparatus of claim 1, further comprising means forrestricting the staples from premature discharge.
 7. The apparatus ofclaim 1, wherein each chamber defines a detent into which the associatedstaple is free to deform.
 8. The apparatus of claim 1, furthercomprising a lever, a drive mechanism and hand piece with a trigger,wherein the lever allows the drive mechanism to be rotated after thetrigger has been initially activated.
 9. An apparatus as claimed inclaim 1, in the form of a medical stapler.
 10. The apparatus as claimedin claim 9 including a cap for holding a graft on an end of the stapleruntil the staples are deployed.
 11. A method of fastening using theapparatus of claim 1, including placing staples into the chambers of theapparatus, in a straightened configuration, moving a sleeve between afirst position, in which the staples are trapped by the sleeve withinthe chambers, and a second position whereby the staples are freed toadopt the deployed condition.
 12. The method of claim 11, for attachinga graft, wherein the graft is initially carried by the apparatus untilsecured in place using the staples.
 13. The method of claim 11, furthercomprising using the apparatus to form end to end or end to side jointsof tubular bodies with multiple joining staples.
 14. A device fordelivering shape-memory staples, the device comprising: a handle formedas a pistol grip; a trigger actuator coupled to the handle; a drivemechanism coupled to the trigger actuator and the handle; and a deliveryportion coupled to the drive mechanism, the delivery portion comprisingretention walls for retaining the staples within the delivery portion inan elastically deformed configuration and release apertures forreleasing the staples to adopt a deployed configuration based on theirshape memory, wherein the delivery portion is configured to cause oneend of each staple to protrude from the delivery portion in response toactuation of the trigger actuator.
 15. The device of claim 14, whereinthe trigger actuator is configured to be actuable by squeezing fingersof a hand when the hand grasps the handle in the manner of a pistol. 16.The device of claim 14, wherein actuation of the trigger actuator causesrelative movement of at least one clutch member within the drivemechanism to cause movement of at least one part of the delivery portionrelative to at least one other part of the delivery portion inpreparation for delivery of the staples.
 17. The device of claim 14,wherein the handle comprises a trigger-positioning ratchet forfacilitating positioning of the trigger actuator relative to handle. 18.The device of claim 14, wherein the trigger actuator is actuable in afirst step to cause the device to adopt a partially actuated state andin a second step distinct from the first step to cause the device toadopt a further actuated state.
 19. The device of claim 14, furthercomprising a release actuator actuable to cause the release of thestaples through the release apertures.
 20. The device of claim 19,wherein the device is configured to only allow actuation of the releaseactuator after full actuation of the trigger actuator.
 21. The device ofclaim 14, wherein the device is configured to deliver staples formed ofwire.
 22. The device of claim 14, wherein the retention walls define aradially inward detent for at least partly engaging respective staplesto promote axial movement of the staples in a distal direction.
 23. Thedevice of claim 14, wherein the release apertures are formed asgenerally longitudinally extending slots.
 24. The device of claim 14,wherein the delivery portion further comprises insertion apertures forallowing insertion of the staples between the retention walls.
 25. Thedevice of claim 24, wherein the insertion apertures are positioned closeto, but radially offset from, the release apertures.
 26. A device fordelivering shape memory staples, the device comprising: a grippableportion; a delivery portion coupled to the grippable portion, thedelivery portion comprising retention walls for retaining the stapleswithin the delivery portion in an elastically deformed configuration andrelease apertures for releasing the staples to adopt a deployedconfiguration based on their shape memory, wherein the delivery portionis configured to cause one end of each staple to protrude from thedelivery portion in response to actuation of the first actuator; and ahead portion positioned at a tip of the delivery portion, the headportion being retractable in a proximal direction to cause the tip toflare outwardly.
 27. The device of claim 26, wherein slots are formed inthe tip to interrupt a distal periphery of the tip and wherein amaterial of the tip is elastically deformable.
 28. The device of claim27, wherein the tip is configured to allow the staples to protrude fromthe tip when the tip is flared, whereby staples delivered from theflared tip are released at a radially increased position relative towhen the tip is not flared.